2.2 : Semi Analytical Models

The galaxy catalogues that are stored in the Millennium database are the products of
two separate, independent semi-analytical algorithms for galaxy formation: L-galaxies at the MPA
and GalFormat the ICC Durham. The pages linked to in the list above summarise these algorithms,
paying particular attention to the
the different definitions of the halo merger trees used as the sekeletoin on which the algorithms work.
These differences are reflected in the distinct data models to store them and special care must be taken to
make comparisons between them as will be discussed elsewhere.

For more details about the semi-analytical galaxy formation algorithms used for the published catalogues
and their results following main references:
For L-Galaxies: Croton2006a
and DeLucia2006b,
For GalForm: Bower2006.